It's not a problem for your nipples to reach the collar ring because that's still only halfway down the tunnel. If they're stretching much past the collar ring, though, it may help to remove lubrication so the sides of the silicone tunnel can hold the nipples in place without stretching, which should also allow the milk to flow more easily.
See our article about lubrication.
Reviewed by Diana West, IBCLC
June 10, 2021